Differential Diagnosis for Swelling of the Lateral Foot
Single Most Likely Diagnosis
- Ankle Sprain: This is the most common cause of lateral foot swelling, often resulting from inversion injuries that stretch or tear the ligaments on the outside of the ankle.
Other Likely Diagnoses
- Peroneal Tendinopathy: Inflammation or degeneration of the peroneal tendons, which run along the lateral side of the ankle and foot, can cause swelling and pain in this area.
- Lateral Foot Fracture: Fractures of the bones on the lateral side of the foot, such as the cuboid or the base of the fifth metatarsal (Jones fracture), can cause swelling.
- Gout or Pseudogout: These conditions can cause sudden, severe swelling and pain in the foot, including the lateral side, due to the deposition of urate or pyrophosphate crystals within the joints.
Do Not Miss Diagnoses
- Compartment Syndrome: A serious condition where increased pressure within the compartments of the foot can lead to nerve and muscle damage. It requires urgent medical attention.
- Deep Vein Thrombosis (DVT): Although less common in the foot, DVT can cause swelling and requires immediate medical evaluation to prevent pulmonary embolism.
- Infection (Cellulitis or Abscess): Bacterial infections can cause swelling, redness, and warmth in the affected area. They need to be treated promptly to prevent serious complications.
Rare Diagnoses
- Erythromelalgia: A rare disorder characterized by burning pain, heat, and redness in the hands and feet, which can also cause swelling.
- Complex Regional Pain Syndrome (CRPS): A chronic pain condition that can cause swelling, among other symptoms, usually after an injury or trauma.
- Tumor (Benign or Malignant): Although rare, tumors can cause swelling in the foot. Examples include soft tissue sarcomas or metastatic disease to the foot.